Two carts, of inertias m1 and m2, collide head-on on a low-friction track. before the collision, which is elastic, cart 1 is moving to the right at 14 m/s and cart 2 is at rest. after the collision, cart 1 is moving to the left at 6 m/s . if the positive direction is from left to right, what is the speed of cart 2 after the collision?

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?